This adds the time when a log message is displayed.
ARDOUR_UI::display_message() parses the prefix,
so the timestamp cannot be prefixed in the beforehand.
Still, UI::process_error_message() is called directly in
the same thread, so this makes no significant difference.
This fixes Audio/MIDI alignment when recording normally.
Loop and/or Punch-in recording is still not aligned properly
(both audio and MIDI).
_accumulated_capture_offset is initialized once, accumulated
offsets (rec_nframes) are kept, even when ::check_record_status()
is called multiple times.
Bug was introduced in 8ed33f1bc7 symbol visibility setting
in CFLAGS, CXXFLAGS was overridden. This resulted in publicly exposed
and bound kiss_fft symbols in libqm-dsp.
At runtime those symbols were resolved using previously bound
symbols in libcodec (see below) that uses a mismatching implementation
(ardour/qm-dsp uses -Dkiss_fft_scalar=double)
#0 0x00007fffea793d40 in kiss_fftr () at /usr/lib/x86_64-linux-gnu/libcodec2.so.0.8.1
#1 0x00007fffcf4516ab in FFTReal::D::forward(double const*, double*, double*) (this=0x5555571d73a0, ri=0x55555a734810, ro=0x55555a7262b0, io=0x55555a728590)
at ../libs/qm-dsp/dsp/transforms/FFT.cpp:121
#2 0x00007fffcf4510fd in FFTReal::forward(double const*, double*, double*) (this=0x555559868190, ri=0x55555a734810, ro=0x55555a7262b0, io=0x55555a728590)
at ../libs/qm-dsp/dsp/transforms/FFT.cpp:186
* update AFL position when preference changes
* "after post-fader processors (before pan)" is before
the main-out (not at the end).
* Fix "immediately post-fader":
The amp, when added was the last element. ++after_end then
made the iterator point to .end()
This likely worked in the past when the monitor send was added
immediately after adding the fader/amp before any other processors.
